Automotive steering columns are typically equipped with kinetic energy absorption devices to reduce injury of the vehicle operator in event of a collision during which the operator impacts the steering wheel, causing the column to collapse.
Such energy absorbing steering columns generally include a jacket that translates linearly through a collapse stroke during a collision. A force generated by the driver from an impact with the steering wheel initiates the collapse stroke. The steering wheel jacket moves against a resisting force that may be produced by an energy absorber designed to convert a portion of the driver's kinetic energy into work. The resisting force may be generated utilizing systems currently known in the art, including the plastic deformation of a metal element that is a part of an energy absorbing device.
Typically, the column assembly is secured to the vehicle structural member that may be part of its instrument panel or a cross-car beam. As is well-known in the art, the column jacket is provided with a mounting bracket having capsules fitted thereto through which bolts extend, the capsules being dislodged from the column mounting bracket as the column strokes during collapse, thereby permitting forward translation of the column relative to the vehicle structural member while the capsules remain secured to the vehicle structural member, the forward translation of the column being against the resisting force of the energy absorbing device.
The mounting bracket and its capsules also provide the means for vertically supporting the end of the column nearest the hand wheel, and upon release of the capsules from the mounting bracket during column collapse, the column assembly and the steering wheel, now no longer vertically supported through the capsules' being secured to the vehicle's structural member, may drop into the driver's lap and impede his extrication from the vehicle after the collision. It has been found desirable, and becoming increasingly required, that the steering column remain upwardly supported away from the driver after collapse of the column during crash. Thus, there is a need for a collapsible steering column assembly that provides such a feature, preferably at low cost and without great complexity. It is further desirable that such a column assembly also be provided with driver-adjustable rake and/or telescope positioning features often found in prior vehicles.